Asians risk of age-related blindness equals whites

NEW YORK (Reuters Health) - Aging Asians appear to be as vulnerable to age-related vision loss as their white counterparts, a new review and analysis of the medical literature shows.

Age-related macular degeneration, or AMD, is a leading cause of blindness in older people. In AMD, the center of the retina deteriorates, causing people to lose their sharp central vision. Studies have found nearly 30 percent of people over age 75 have the disease, according to the National Eye Institute, and rates are rising around the world.

The conventional wisdom has been that Asians are less likely to develop AMD than whites, based on studies in hospitalized patients. But this type of study doesn't really show how common a disease is in the general population.

To investigate, Dr. Ryo Kawasaki of the University of Melbourne in Australia and colleagues looked at nine different studies done in four different Asian populations, comparing the rates of both early AMD and advanced AMD in Asians to estimates in whites.

Among 40- to 79-year-old Asians, the researchers found, 7 percent had early AMD, while less than half a percent had advanced disease. These percentages are comparable to what's been seen in age-matched whites (9 percent early AMD and less than 1 percent advanced AMD).

Asian men, the researchers found, were more likely than white men to have late-stage AMD, while the reverse was true for women. The researchers were unable to compare risks in people 80 and older because there were too few study participants in this age group.

Some researchers have suggested that certain subtypes of AMD might be more common in Asians than whites, Kawasaki and colleagues note. Further research is needed, they conclude, to better explain why early AMD is less common among Asians, and why it is relatively rare among Asian women.